Who ever merges this, please backport to v1.5.3-doc

@NelleV did you do the backport?

Yep, I did.
Is there a way to run travis on other branches than master? That's going to be very annoying to fix on my computer, considering I can't built the doc with warnings treated as error.

backported to v1.5.3-doc as 5c548e5

Hum… sorry. Yes I did the backport, but the documentation built fails. Hence my very unclear previous message…

It is very odd that it passed on master, but not on v1.5.3-doc..... I will take a look at this (me and sphinx are getting to know each other too well).

In the meantime, I'm doing another attempt at setting up my dev environment to build the sphinx documentation with the same options as on travis. I'll keep posted if I have any luck.

The docs build cleanly for me locally, I restarted travis on this branch (accidentally for the full matrix :/)

but with python 3.5 + sphinx 1.4.6 not py2.7 + sx1.3.1

@NelleV, doc/make.py has a command-line argument:

parser.add_argument("--allowsphinxwarnings",
                    help="Don't turn Sphinx warnings into errors",
                    action="store_true")

Docs appear to still not be building.